Field of the Invention
The present invention relates to an improved cover system for flat bed vehicles and, more particularly, to a tarpaulin type cover system which may be erected and removed as desired to cover or uncover the space above the flat bed.
Flat beds trailers have been used for many years to haul a wide variety of loads. The flat bed facilitates loading onto the trailer as there are no walls to restrict or impede access thereon. However, in order to protect and/or contain the loads, it is often desirable to erect a structure covering the top and sides of the load. For such purposes, many flat bed trailers are provided with stake bodies on which may be erected rigid sidewall assemblies and a fabric tarpaulin type top cover. Usually the sidewall assemblies, which are known as side kits, include a number of wooden posts or stakes, wooden side boards, a wooden headboard panel, and a wooden tailgate panel. The posts are received in rectangular shaped brackets which are mounted at regular intervals along the length of the flat bed and receive the side boards. The posts are provided with a socket at the top end to receive inverted U-shaped bow members of metal construction which extend over the load between the sidewalls formed by the sideboards. The fabric top cover extends over the bows and overlaps the sidewalls, with tie down ropes being used to secure the top cover to the flat bed.
A significant disadvantage of the cover system just described is its weight. It is estimated that the weight of a side kit for a 48 foot long flat bed trailer having 1/2 inch thick panels and sideboards is approximately 640 pounds. This is a significant amount of extra weight, especially given the fact that quite often the side kit is not being used but must nevertheless be stored on the trailer. Excess bulk and weight can also be a significant disadvantage to a truck driver as the driver cannot count on the availability of any assistance in erecting or removing the cover system.
In the past, tarpaulin cover systems have been devised to cover both the top and sides of a flat bed trailer, thereby avoiding certain disadvantages associated with conventional cover systems employing wooden side kits. However, such systems have other disadvantages which have prevented any of these systems from coming into widespread use. For example, many of these types of cover systems employ mechanical retraction and extension systems which are themselves expensive, heavy and/or unreliable.